The present invention relates to a paper feeding arrangement for a printer, copier and other recording apparatuses and, more particularly, to an improvement in the connection between such a recording apparatus and a mass feed unit for feeding a large amount of paper sheets, stack unit for stacking paper sheets discharged, re-feed unit for conditioning copies for re-feed, and other optional units, as well as in the connection between such units themselves.
Generally, in a recording apparatus of the kind described, a paper sheet or like recording medium fed into the apparatus and, then, subjected to a recording or copying process is driven out of the apparatus. While many of such recording apparatuses are provided with a medium feed and a medium discharge system in its housing, there is an increasing demand for, in addition to those systems, a mass feed section having a greater capacity than the conventional medium feed system as well as for a capability of allowing the medium to be selectively discharged in various different modes. To meet this demand, there have been proposed a recording apparatus having a mass feed section in its housing, and a recording apparatus selectively operable with independent units which may be connected to the apparatus as needed. A drawback with the first-mentioned approach is that the apparatus is bulky and, because the mass feed section is not separable from the housing, incapable of integrating various functions according to user's demands. On the other hand, the second-mentioned approach has a problem that the function attainable is not more than a simple paper handling function since the optional units to be connected are not identical in the manner and/or the structure for connection. In addition, in the case that the direction of paper transport differs from one unit to another, there has to be used those units the manner and structure for connection of which are identical with regard to the direction of paper feed.